An explosion of social media has catapulted the shooting death of Florida teenager Trayvon Martin into the national spot light, with a single petition calling for his killer's arrest now the fastest growing petition in internet history, according to Change.org.

Martin, 17, was killed by self-appointed neighborhood watch captain George Zimmerman Feb. 26. Just moments before Martin is killed, Zimmerman, who is white, can be heard muttering something in a call to the police dispatcher which many believe was a racial epithet.

Martin, who was black, was carrying only a bag of skittles, ice tea and his cell phone which captured his last seconds in a phone call with his girlfriend before he was shot to death.

Martin's family says that what the girl heard contradicts Zimmerman's claim that Martin was acting suspiciously and was the aggressor in their confrontation.

The family has called for Zimmerman to be arrested

For nearly three weeks the story languished, as did the change.org petition set up for Martin's parents Sybrina Fulton and Tracey Martin. It had a few thousand signatures, but towards the end of last week, as ABCnews.com other media began intensifying their coverage of the story and celebrities tweeted about it, interest in the story soared.

A host of celebrities from hip hop icon and entrepreneur Russell Simmons to new age leader Deepak Chopra to director Spike Lee have written and tweeted calling for justice for Martin

Some celebs used their pulpits to drum up awareness while others issued warnings, with Simmons tweeting this last week : "Trayvon Martin didn't die so we can create a race war he died so we can promote better understanding. We must start honest dialogue."

Black radio and television hosts have also bouyed the story, calling on authorities to act.

Amid the growing chorus of statements, Florida authorities announced that they would convene a grand jury and the Department of Justice said they would investigate Martin's shooting as a possible hate crime.

The growing support for the Martin family is seen in the accelerating pace of signatures on the Martin family's Change.org petition to have Zimmerman arrested.

"The explosive petition to bring justice for Trayvon Martin was started just days ago by his parents and is already the all time fastest-growing petition on Change.org," the group told ABC News today. "With up to 800 people signing per minute, and 250,000 petition signatures since yesterday morning, the growth is unprecedented."

So far, nearly 800,000 people have signed the petition.

There are 15,000 petitions launched on Change.org every month, the statement said.

"People worldwide are shocked by Trayvon's killing, and they're turning to social media like Change.org and Twitter to turn that outrage into action," the statement said.

Benjamin Walt-Jaffee of Change.org told ABC News that unlike Facebook, Twitter or Youtube, where a simple click of like indicates support, the signatories of the petition must provide their full name, a functioning email address and home address for their signature to be counted.